Ionized magnesium in gestational diabetes.

A longitudinal prospective study was performed in order to describe variations in ionized magnesium in patients with gestational diabetes. Twenty-two gestational diabetic women and 24 healthy pregnant women were included consecutively. Blood samples were obtained in the second and third trimester and 2 days postpartum in both groups. The blood samples were analysed for serum ionized magnesium, serum ionized calcium and pH. None of the groups demonstrated any time-related changes in ionized magnesium. However, in the third trimester the level of ionized magnesium was statistically significantly elevated in patients with gestational diabetes compared to controls (0.57 +/- 0.05 mmol/l vs. 0.51 +/- 0.06 mmol/l; p < 0.01). The level of ionized calcium remained stable throughout the study period in both groups. In conclusion our findings suggest that gestational diabetes is associated with elevated levels of ionized magnesium.